1. Field of the Invention
The present invention relates to a moving image data processing apparatus and a moving image data processing method and, in more detail, relates to a moving image data processing apparatus and a moving image data processing method that make it possible to easily play back moving image data generated at various frame rates at a predetermined frame rate and playback speed.
2. Description of the Related Art
In recent years, a user sets different frame rates according to imaging data to capture various scenes and subjects, which has become common not only in business use imaging apparatuses but also in home use imaging apparatuses. The following is an example of image capture using different frame rates.
In image capture of scenes of a travel, a birthday party of a user's family, and the like, general frame rates such as 30 fps (Frames Per Second) and 60 fps are used. In contrast, when a user wishes to obtain imaging data that allows the recognition of the smooth motion of a subject even if the motion of the subject is quick for example when capturing a sport scene and the like, high frame rates such as 300 fps and 600 fps are used. Moreover, when a user captures a subject that makes subtle changes over a long time for example, when capturing a plant growing scene, low frame rates such as 1/20 fps and 1/80 fps are used.
A frame rate of 1/N fps (N is an integer equal to or more than one) such as 1/20 fps and 1/80 fps used here indicates a rate at which a frame related to one still image is captured at a predetermined moment in every N seconds. Therefore, for example at 1/20 fps, generated is a frame where a scene/subject is captured at a specific moment of every 20 seconds.
Thus, it is desirable that imaging data generated at various frame rates at the image capturing can be played back at various frame rates and playback speeds when viewing for the purposes. Moreover, some playback apparatuses can originally play back imaging data only at a limited frame rate, such as only at 60 fps.
For example, it is desirable to play back 10 minutes' imaging data at 600 fps, which has been generated by capturing a sport scene at 600 fps for 10 minutes, for the purpose of viewing the smooth motion of a subject image. On the other hand, for the purpose of playback in slow motion and checking minute points of the subject image, playback at a lower frame rate (for example 60 fps) and a lower playback speed (for example a playback speed of 100 minutes for all the imaging data) may be desired.
Moreover, in a case where a display apparatus viewed by a user is originally designed only at a limited frame rate (for example 60 fps), after captured frames are processed with decimation or interpolation (for example decimated so that the total number of the frames becomes 1/10) so that a playback time from start to end be set to the same 10 minutes and played back at a speed same as the original captured imaging data. In addition, also in this case, it is also desirable that the playback speed can be made faster or slower.
This is the same for a moving image data captured at a lower frame rate than at a normal rate.
Imaging data generated at a frame rate of 12 fps upon image capture, if viewed at a higher frame rate, can generally be seen of the change of a subject in a shorter time than the actual image capture time. On the other hand, in a case where some kind of a change is to be checked in detail and where an operation is to be edited into a certain stage of the image, playback at a slower speed than the viewing may be desired.
While it is becoming common to generate imaging data, or moving image data at various frame rates, there is much room for improving an environment where a user plays back these moving image data at a desired frame rate and at a playback speed. For example, even if users wish to sequentially/continuously play back a plurality of imaging data generated at different frame rates, many users are in an environment where a frame rate and a playback speed that are used for playback need to be appropriately set for each piece of the imaging data. Moreover, as described above, some display apparatus a user has may be originally set to playback only at a limited frame rate, such as 30 fps and 60 fps.
Considering into what is described above, have been developed an imaging apparatus and a playback apparatus for generating imaging data (moving image data) at different frame rates, and allowing a user to more easily play back the plurality of moving image data generated at the different frame rates. For example, Japanese Patent Application Laid-open No. 2008-288924 describes a moving image capture apparatus and a moving image playback apparatus that can playback with a simple operation at a slow motion speed or quick motion speed that a person who captured the image intends.
The moving image capture apparatus described in Japanese Patent Application Laid-open No. 2008-288934 includes a frame rate setting unit that arbitrarily sets: a recording frame rate indicating the number of frames per unit time while capturing a moving image; a valid frame rate indicating the number of frames per unit time of valid frames that are moving image playback targets out of frames captured as the moving image; and a playback frame rate that is the number of frames per unit time while playing back the valid frames, respectively. The recording frame rate, valid frame rate, and playback frame rate are associated with each other to be recorded in a recording medium. The moving image playback apparatus and the like refer to these pieces of information upon playback; and accordingly a user can perform playback in slow motion or quick motion that a person who captured the image intended, and can perform smooth playback when the playback speed is changed.
However, the imaging apparatus described in Japanese Patent Application Laid-open No. 2008-288934 sets and records the recording frame rate, the playback frame rate, and the valid frame rate upon the generation of imaging data. Therefore, even when a user wishes to change the frame rate at the time of playback to a different frame rate from the three kinds set upon the image capture, it is considered to have a problem that the imaging data can be played back only at any of the frame rates. The same issue occurs in the playback speed.
When a plurality of imaging data with different frame rates are to be sequentially or continuously played back, and when a user wishes to set a frame rate and playback speed used for their playback to be predetermined frame rate and playback speed, there can be a problem that a user needs to set a frame rate at the time of image capture considering into the playback speed. In addition, the user must consider and set the three kinds of frame rates, the recording frame rate, the playback frame rate, and the valid frame rate, which is troublesome for the user in the first place and which may give a load to the imaging apparatus.